Buffer device for draft gears and the like



July 27 1926. 1,593,761

| E. ENDSLEY BUFFER DEVICE FOR DRAFT GEARS AND THE LIKE Fi1 ed March 241925 PATENT OFFICE.

, Louis E. nnnsnnr, or rrr'rsianrtsir, PENNSYLVANIA.

BUFFER DEVICE roa DRAFT onansnnn THELIKEL Application filed Marcl1 24,1325. Serial N-o.. 1f?,958..

My invention relates to buffer devices for draft gears and the like, andis particularly.

applicable to those structures wherein spring steel plates areemployedas shockabsorbing elements.

One object of my invention is to provide meanswhereby a spring steelplate or plurality of plates are stressed substantially uniformly at allponits throughout their length WllGIl deflected, as compared to thosestructures wherein the stress on a plate at the central portion only ismaximumand the stresses at points removed from said central portion arereduced ifrom the maximum stress to zero. 1

Another object of my invention isvto increase and improve generally theabsorbing capacity of a given number of spring plates.

One mannerin which my. invention may be. practiced is shown in theaccompanying drawing wherein Fig. -1 is a sectional view showing a'general arrangement of draft gear rigging for railway cars in which myinvention. is incorporated, and Fig.v 2-is. a view. onan enlar ed scale,of a portion of theapparatus of Fig. 1 and illustrating my inventiondiagrammatically.

I-Ieretofore it has been customary, in employing spring steel plates asshock absor ing members, to cause deflection thereof upon a surface thatis uniformly curved or that has a single radius. The objection to thisarrangement arises .fromthe fact that the spring plates are subjected tovery great stresses atthe point where deflection begins, and to.comparatively little stress at points removed therefrom. For,v instance,if. a spring plate 012a plurality of plates are placed upon .a. surfacehaving uniform. curvature and the ends of the plates deflected untilthey Contact with such. surfaces throughout their length, the plates .attheir mid portions may be under a'stress of-120,- 000 lbs. atv givenpoints on either side of said first-named point the stresses may be but115,000 lhs. at points still farther removed, the stresses may be 90,000lbs; still farther away the plates may be under a stress of but 7 0,000lhs., while at the extreme ends of the curved plates their stresses willbe zero.

By providing, for the spring plates, a seating surface having an,initial curvature of a given radius and changing the curvature of saidsurface at points removed from the initial point so that a plurality ofcurves of progressively smaller radii are provided,

I am enabled to effect a substantially uniform stress on the springplates at all points throughout their length. Thus, by thisarrangement,the plates in the first zone of deflection may be under a stress of114,000 lbs, in the second zone .(at. each side of the first zone) theymay be under a stress of 114,000 lbs, and also under stresses, of114,000 lbs. in the third and fourth zones, as compared. to the stressesenumerated above in connection with theformer types of buffers. Thusthere is a uniform stress to sub stantially the end of the. plates. i

In the drawingl have shown a draft sill or beam 3 provided with followerstops 4 and 5. A yoke 6 of the usual form may be employed. A pluralityof sets of spring steel plates 7 are also provided; The plates 7 aremounted. between a rear follower 8 and a front follower 9, and spacers10 and 11 are interposed between the groups of plates 7.

Thespacing plates 10 are concave so that only their end portionsWillengage .with the spring plates 7, even during deflection there. of.The end group of platesare-deflected about the curved surfaces of thefollower plates 8 and 9, and the two intermediate groups of..platesaredeflected about the cur-vedfaces of the convex spacer block 11.

The. curvatures ofthe plate contacting surfaces of the blocksS, 9 andllare preferably thesame, so that adescription of the curvature'of thefollower block 8 will suflice alsofor blocks 9 and 11. y

In .Fig. 2 I-have shown only one-half of the follower 8, since thecurvature at each side of its central portion is the same. The radius ofcurvature.ofthe follower 8 in the zone marked a is such that when theplates are. bent into contact with the follower throughout the distancea, they are under maximum stress, Within the zone I) the follower 8 hasa curve of less radius than that of zone a. Therefore, furtherdeflection of the plates 7 is-required inorder to bring them intoengagement with that portion of the follower 8 lying withinzone b. Thatportion of the plates overlying zone bis likewise under maximum stress(114,000 lbs, for example). The follower 8 has a curvature of stillshorter radius within the zone 0, and likewise with respect to zone d.The dotted line 12 indicates a true arc struck from the radius of themid-portion .ofthe follower 8.

faces on blocks 8, 9 and ll, respectively, which have curvatures ofsuccessively shorter radii, and thereby utilize the yielding capacity ofthe spring plates to their fullest extent, as compared to the olderstructures, wherein a single curved surface of uniform arcuate shape isemployed. and wherein the plates are under maximum stress at theirinidportions. The seating surface could obviously be of elliptical form,if desired.

Below is a table of actual tests made, under similar conditions, with afollower block of the usual uniform radius and my special form of blockhaving non-uniform radii. The readings were obtained by a strain gage ofa, well li'i'iown type, and show that as deflection of the spring platesincreased against the surface of the standard type of follower there wasa very rapid de crease in stress, as compared to the almost uniformstress in the case of my follower, up until the three-inch mark.

illrr'rimim: ell-cases in plates.

Follower having radii decreasing from 29 to 17 27% radius Location onplate Std follower Stress.

Center 1% ofi cent 3" off center" 4% oiT center" under stresses greaterthan would be the case when employed against a surface having uniformcurvature, and that I do not limit myself to certain degrees ofcurvature nor to he number of zones of deflection.

- in as my invention: a draft gear structures, a pair of spaced followerblocks having seating sur- "aees sprin steel plates disposed betweensaid surfaces, and a double concave spacer between said plates, each ofsaid surfac r having a curvature of a given radius at 1., normal pointof contact with one of said and having a curvature of shorter at pointsremoved from said normal point. 'i

it: draft gear structures, a pair of spaced follower blocks havingseating surfaces, spring steel plates disposed between said surfaces,and a double concave spacer between said plates, each of said surfaceshaving a curvature of a given radius at its normal point of. contactwith one of fsaid plat plates, and having curvatures of progressivelyshorter radii at points successively removed from said normal point.

3. In draft gear structures, a pair of spaced follower blocks havingseating surfaces, spring steel plates disposed between said surfaces,and a double concave spacer between said plates, each of said surfaceshaving a. curvature of a given radius at its normal point of contactwith one of said plates, and having curvatures of progressively shorterradii to either side of said normal point, at points successivelyremoved therefrom.

t. Buffer structure comprising a seating block, a spring steel platenormally engaging said block at one portion of its surface, and impactreceiving means for deflecting said plate into engagement with anotherportion of said surface, the first named portion being formed to causethat part of the spring adjacent thereto to assume one ourvature, andthe second named portion being formed to cause that part of the springengaging therewith to assume a curvaturehaving a different radius thanthe curvature of the first-named portion.

5. Buffer structure comprising a curved seating block, a. spring platenormallyengaging said block at its mid-portion, and impact receivingmeans for deflecting said plate into engagement with portions of saidblock to either side of said mid-portion, the last-named portions ofsaid block being curved about radii of different length than the radiusof said mid-portion.

6. Buffer structure comprising a curved seating block, a spring platenormally .engaging said block at its mid portion, and impact receivingmeans for deflecting said plate into engagement with a plurality ofportions at each side of said mid-portion, the engaging surfaces of saidplurality of portions having curvatures of progressively shorter radiiat points successively removed from said mid-portions.

7. The combination with a spring metal plate, of a seat therefor havinga curvature of generally arcuate form but of varying radii, and animpact receiving member for deflecting said plate against said seat.

8. The combination with a. spring metal plate and a support therefor, ofa forcetransmitting member having engagement with said plate at a pointremoved from the said support, and means limiting the bending movementof said plate but permitting increased bending movements thereof atpoints successively removed from said support.

In testimony whereof I, the said LoUIs E. EivnsLnrg'have hereunto set myhand.

LOUIS E. ENDSLEY.

